1. Field of the Invention
The present invention relates to a volume controlling technique in an audio system, and more particularly to a volume reservation apparatus and method of an audio system for preprogramming volume of sound to be produced and supplying the preprogrammed volume of sound at a preset wake-up reservation time.
2. Description of the Prior Art
A volume controlling apparatus of a general audio system, as illustrated in FIG. 1, includes a remote controller 1 for supplying a signal corresponding to a key selection manipulated by a user among various keys (not shown) thereon to remotely control the operation of the audio system in terms of the user's desire. Also, a microcomputer 2 receives a signal from the remote controller 1 to control overall operation of the audio system, and a display unit 3 displays predetermined alphanumeric representation under the control of the microcomputer 2. A stepper motor 4 rotates a shaft thereof clockwise or counter-clockwise in response to a driving pulse from the microcomputer 2, so that a variable resistance adjusting plate 5 coupled to the upper portion of the shaft is rotated clockwise or counter-clockwise. Upon the rotation of the variable resistance adjusting plate 5, a belt V placed along the side of the variable resistance adjusting plate 5 travels to vary a resistance value of a variable resistor 6. In addition to these, the volume controlling apparatus has an amplifier 7 controlled by a variable output of the variable resistor 6 according to the variable resistance value, for amplifying a received audio signal Au by a predetermined amplification factor to supply the amplified audio signal toward a speaker SP.
An operation of the volume controlling apparatus of the audio system constructed as above will be briefly described as below.
When the user presses a volume-up key (not shown) of the remote controller 1 in order to raise volume of sound produced from the audio system, a signal corresponding to the volume-up key is supplied from the remote controller 1 to the microcomputer 2 in the form of an infrared signal or high frequency signal.
Otherwise, if the user presses a volume-up key (not shown) on an unshown main body of the audio system in order to raise the volume of sound produced therefrom, a signal corresponding to the volume-up key is supplied to the microcomputer 2.
At this time, the instance of pressing the volume-up key on the main body of the audio system will be omitted for the purpose of simplifying the description.
Then, the microcomputer 2 receives an output signal of the remote controller 1 via a remote signal input terminal IN, and supplies a driving pulse P1 to an input terminal + of the stepper motor 4 via an output terminal OUT1 thereof.
By this operation, the stepper motor 4 is driven to rotate its shaft clockwise, i.e., in the direction to raise the volume, so that the viable resistance adjusting plate 5 coupled to the upper portion of the shaft is rotated clockwise. At the same time, the belt V provided along the side of the variable resistance adjusting plate 5 travels clockwise by as long as a predetermined distance to vary the resistance value of the variable resistor 6, thereby varying the output of the variable resistor 6.
It is a well known structural expedient in the art that the variable resistance adjusting plate 5 can be manually rotated clockwise or counter-clockwise by the user in a direct manner.
The amplifier 7 is controlled by the variable output of the variable resistor 6 to amplify the input signal, i.e., the audio signal Au reproduced from a magnetic tape or disc, thereby supplying the amplified signal to the speaker SP.
Meanwhile, if the user presses a volume-down key (not shown) of the remote controller 1 to lower the volume of sound produced from the audio system, a signal corresponding to the volume-down key is supplied from the remote controller 1 to the microcomputer 2.
The microcomputer 2 receives the output signal of the remote controller 1 via the remote signal input terminal IN, and supplies a driving pulse P2 to an input terminal - of the stepper motor 4 via an output terminal OUT2 thereof.
By this operation, the stepper motor 4 is driven to be rotated counter-clockwise, i.e., in the direction to lower the volume, so that the variable resistance adjusting plate 5 is rotated counter-clockwise. At the same time, the belt V travels counter-clockwise by as long as a predetermined distance to vary the resistance value of the variable resistor 6, thereby varying the output of the variable resistor 6.
The amplifier 7 is then controlled by the variable output of the variable resistor 6 to deamplify the input signal, i.e., the reproduced audio signal Au, thereby supplying the deamplified signal to the speaker SP.
According to the above-described method, the user adjusts the volume of sound from the speaker of the audio system in a remote distance or manually.
On the other hand, when the user preprograms a sleep-time reservation by pressing a sleep-time reservation by (not shown) of the remote controller 1 or a wake-up time reservation by pressing a wake-up reservation key (not shown), the microcomputer 2 receives a signal from the remote controller 1 to determine whether the received signal is for preprogramming the sleep or wake-up time, and stores the reservation time in a storage unit therein while displaying the reservation time on the display unit 3.
Therefore, the microcomputer 2 stops the sound from the speaker SP of the audio system when the current time coincides with the sleep reservation time in case of the sleep-time reservation; whereas it initiates the operation of the audio system to output the sound via the speaker SP when the current time coincides with the wake-up reservation time in case of the wake-up time reservation.
In the conventional audio system, however, if the user preprograms the wake-up time reservation or preprograms the sleep-time reservation and then wake-up time reservation under the state that the volume of sound from the speaker is low, the volume-down sound prior to preprogramming the wake-up time is produced from the speaker when the current time coincides with the preprogrammed wake-up time with the consequence of deteriorating the effect of satisfactory wake-up indication.
In other words, the conventional audio system has no volume reservation function involving a drawback that the sound of desired volume cannot be supplied at the preprogammed time.